Deck swimming pool covers, and the associated cover drums, cables, reels and drive systems are typically housed in a bench type enclosure positioned at one end of a swimming pool. The pool side of the enclosure is typically cut away to allow extension and retraction of the cover. Because of the location of the bench-type enclosure at one end of the swimming pool it frequently is used as a bench for a variety of purposes at the side of the pool.
Typically, a beam which is composed of two materials properly bonded together and having different moduli of elasticity is called a composite beam. Reinforced concrete beams, steel beams mechanically bonded to a concrete deck, and wood beams reinforced with steel plates are typical examples. The analysis of composite beams depends on the assumption that a plane section before bending remains plane after the load is applied. Therefore, the two materials must be connected in such a way that they will act as a unit. This condition is realized in the reinforced concrete beam by means of the bond between the reinforcing rods and the concrete. In the case of reinforced wood beams, the parts are connected by bolts properly spaced to resist the shearing forces between the plates and the beam.
Presently, however, none of these types of construction are suitable for certain applications, including swimming pool covers.